Annealing furnace



APT 22, 194- l C. B. Hamm 2,239,593

' AMrsmmNG FURNACE Filed Sept. 26, 19%@ 2 Sheets-Sham l April zz, 1941.

INVENTOR `when such hood is in place.

provided for closing the ports I0, or certain of Patented Apr. 22, 1941 p, N UNITED STATES PATENT OFFICE ANNEALING FURNACE Clarence B. Hoak, Steubenville, Ohio Application September'ZG, 1940, Serial No. 358,431

4 Claims.

E `a method and a means for more effectively controlling the amount of heat applied to an annealing box or material being annealed at various points in the furnace, whereby the work is not unduly heated at some points as compared to I other points, and whereby greater economy in fuel consumption can be obtained than in various other forms of annealing furnaces.

Some of the forms which my invention may take are shown in the accompanying `drawings wherein Figure 1 is a cross-sectional view through a `furnace of the type referredto; Fig. 2 ls an enlarged view of a portion of the structure of Fig. 1; Fig. 3 is a sectional plan view taken on the line III--III of Fig. 4; Fig. 4 is a vertical sectional view taken on the line IV-IV of Fig. v1; Fig. 5 is a view partly in plan and partly in section of a modified form of furnace, and Fig. 6 is a cross-sectional view of a portion of the furnace of Fig. 5. g

While the furnace is herein shown as of rectangular form in plan view, it will be understood that my invention is applicable to furnaces of other shapes, including circular furnaces.

Referring first to Figs. 1 to 4, I show a base or foundation that comprises a pair of I-beams l that extend longitudinally of the furnace and are embedded in concrete. I-beams 8 are similarly embedded in the concrete in position to support the ends of the hood or bell. Included within the foundation are tunnels or conduits 9 `that The framework for the hood comprises beams I4 at each lower longitudinal edge of the hood and distributed throughout the length of the hood, short channels I5 being positioned between each of ladjacent beam members 'l and having their ends welded or otherwise rigidly secured thereto. Plates I 6 are welded to the lower edges of the members |4 and I5 and at their inner ends are bent upwardly and backwardly to support burners I'l and the refractory elements forming part ofthe hood Wall. 'I'he burners I1 are may suitably lead to a stack and which, through ports` Ill at various points throughout their length, communicate with the interior of the hood Dampers I I are them, when desired, in vorder to control the flow of gases from the hood. Alining pins or posts I2 are rigidly secured to the foundation at diagonally opposite corners thereof and serve as guide posts or alining pins for ears VI3 that are carried by diagonally opposite corners of the hood, so that the hood can be conveniently and accurately centered upon the base. p

are recessed to receive anchor tiles beams 30 and 3I.

distributed throughout the length of the furnace at each side thereof, as indicated more clearly in Fig. 3.

Upright beam elements i9 that are in the form of channels arranged back-to-back are supported upon the beams |4 and have cross braces 20 welded thereto at their ends. At the ends of the hood, vertically-extending I-beams 2| are provided, said beams being braced by angles 22 disposed between them at intervals and welded thereto. Plates 23 are welded to the bottoms of the uprights 2| and support the end brickwork 24. Metal plates 25 are positioned between the uprights 2| and the brlckwork or refractory lining 24. Similarly, metal plates 26 are disposed against the inner sides of'` the uprights I 9 and brace members 2U, to afford lateral support and protection for the refractory lining 21 along the sides of the hood.

At their upper ends the uprights I9 are connected by welding or otherwise, to I-beams 29 that extend longitudinally of the furnace, and these members 29 are in turn connected by cross- The cross-beams 30 are also secured to the upper ends of the uprights 2|. Channels 33 are secured to the inner sides of the uprights I9, for supporting skewbacks 34 of the furnace arch 35, the arch having a covering of insulating material 36 that is in turn covered by a top plate 31.

Spaced inwardly of the refractory lining 21, at each side of the furnace, is a heat-radiating wall 39 that is composed of a series of slabs 40 whose edges are placed in abutting relation so as to form in effect an unbroken wall at each side vof the furnace, to the front of the path of discharge of the burners The inner faces of the slabs 40 4I through which anchor bolts 42 and 43-extend, the bolts 43 extending through those elements 4| which are inwardly opposite to the vertical channels I9 and Spacer elements 46 are provided between the lining 21 and the radiating wall 39 to hold thev wall in spaced relation to the lining. These j spacers are arranged in vertically aligned rows which are offset from the axial line of discharge of the burners I1, so that the major portion of the burner flames and the heated air will flow in verticallydeflned paths.

Air for combustion at the burners I1 is supplied from a motor-driven fan 48 that communicates through a conduit 49 with a manifold 5U. The manifold 50 extends around the box near its lower edge and is supported by upright plates 5I upon the beams I4. A pipe 52 leads from the manifold 50 to each burner I1. The fan 48 and its motor are mounted upon the top of the hood with a suitable length of Wiring for the motor,

so that the hood can be lifted from the base without interfering with the electrical connections.

Gas or other fluid fuel is supplied to the burners I1 from a supply conduit 54 at each side of the furnace, the conduits being secured to the uprghts I9 and having connection through a flexible hose 55 with a suitable source of fuel supply. The fuel flows from the conduits 54 through pipes 56 to the various burners I1. The pipes 52 and 56 are provided with valves 52a and 56a to control the fuel mixture and also t'o control the amount of flame at each burner, it being understood that in some instances more heat will be required near one end or side of the hood than at the other. lFor example, it often 'will not be necessary to burn as much fuel near the middle of the hood as adjacent to the ends thereof. Damper-covered inspection openings 51 and 58 are provided so that the operator can view the interior of the hood when desired, the openings 58 serving also as a means of access to light the burners I1.

Pillars 59 and 60 are provided for supporting annealing boxes 6I, the pillars 66 serving also to carry the usual sand troughs 62. It will be seen that a considerable amount of heat will be radiated from the walls 39 against the sides of the annealing boxes and that heated gases will pass over the upper edges of said walls into contact with the tops and sides cf the annealing boxes and down between the pillars 59 and 6D to the outlets I6. The amount of radiation from various zones of the partitions 39 can be controlled by regulating the pressure at the burner and hence regulating the height of the flame and the height at which the most intense combustion occurs behind the partitions.

' In Figs. 5 and 6 I show a somewhat different arrangement than in Figs. 1 to 4, in that burners 68 are supplied through the side walls of the furnace and have their inner ends directed upwardly, fuel and air mixtures being supplied from a manifold 63. fuel and air can be supplied separately if desired, as in the case of Fig. 1, and also that this form of fuel supply can be substituted for the separate fuel and air supplies of Fig. 1. Another point of difference inthis structure resides in the fact that the spacer elements 64, that correspond to the elements 46 of Fig. 1, are of greater ver- It will be understood that the.

tical dimension than the spacers 46, so as to more closely confine the upwardly-directed ames and heated gases from the burners, in more definite vertical paths.

The furnace of Figs. 5 and 6 is provided with openings in-its roof, having movable cover plates 66, and these openings may serve as vents for the combustion gases within the furnace, when venting is desired. 'I'his furnace can, of course, be utilized in conjunction with the venting ports I0 and the foundation conduits 9 in the same manner as the furnace of Fig. 1.

It will be uderstood that the partitions or radiating walls need not be built unitarily with the removable hoods, but can simply be supported upon the foundation, inwardly of the burners ,I1 or 68 as the case may be. t

I claim as my invention:

1. An annealing furnace comprising a casing,

laterally-spaced walls disposed interiorly of the casing, one of the walls extending upwardly from the bottom of the furnace and terminating below the roof of the annealing chamber, burners discharging into the space between the walls and spaced from one another in a direction longitudinally of the furnace, at the bottom of said space, whereby the hot gases will move'upwardly through said space and over said one wall, into the annealing chamber, the said one Wall being of heat-radiating material whereby a substantial portion of the heat is passed into the annealing chamber by radiation, and vertically-disposed elements between said walls, in position to direct the major portion of the said gases in defined Vertical paths to the top of the radiating wall.

2. An annealing furnace comprising a casing,

laterally-spaced walls disposed interiorly of the v casing, one of the walls extending upwardly from the bottom of the furnace and terminating below the roof of the annealing chamber, burners discharging into the space between the walls, at the bottom of said space, whereby the hot; gasa: will move upwardly through said space and over said one wall, into the annealing chamber, the said one wall being of heat-radiating material whereby a substantial portion of the heat is passed into the annealing chamber by radiation, and vertically-disposed elements between said walls, in position to direct the major portion of the said gases from each burner in a defined vertical path.

3. An annealing furnace comprising a casing, laterally-spaced walls disposed interiorly of the casing, one of the walls extending upwardly from the bottom of the furnace and terminating below the roof of the annealing chamber, burners discharging into the space between the walls and spaced from one another in a direction longitudinally of the furnace, at the bottom of said space, whereby the hot gases will move upwardly through said space and over said one wall, into the annealing chamber, the said one wall being of heat-radiating material whereby a substantial portion of the heat is passed into the annealing chamber by radiation, and vertically-disposed elements between said walls, in position to direct the majorV portion of the said gases in defined vertical paths to the top of the radiating wall, the laterally-spaced walls and the casing being connected in unitary relation, so that they mayv the roof of the annealing chamber, burners discharging into the space between the walls and spaced from one another in a. direction longitudinally of the furnace, at the bottom of said space, whereby the hot gases will move upwardly 5 through said space and over said one wall, into the annealing chamber, the said one wall being of heat-radiating material whereby a substantial portion of the heat is passed into the anneal- CLARENCE B. HOAK. 

